A large national study suggests that patients at risk of heart disease can reduce their chances of heart attack, stroke, and death by lowering their systolic blood pressure by even more than what is currently recommended.
Authors of the widely anticipated research, published Monday in the New England Journal of Medicine, said the more aggressive approach makes sense despite an increased risk of fainting and kidney problems.
Currently, patients at risk of heart disease are told to lower their systolic pressure - the higher of the two numbers from the measurement in the doctor's office - to 130.
Study authors said patients who lowered that number to about 120 by taking additional drugs were better off than those who made it only to the low- to mid-130s.
The study followed more than 9,300 patients with an average age of 68, including a few dozen from Temple University Hospital and the Hospital of the University of Pennsylvania, for more than three years. Results of the study, funded by the National Institutes of Health, were announced at a scientific meeting of the American Heart Association in Orlando.
Preliminary results were announced via news release in September without the actual number of patient deaths and other outcomes. The lack of data drew criticism from some cardiologists, who said they didn't have the information they needed to guide patients.
Now the numbers are in, and they are big.
Patients in the more aggressive treatment group were given three medicines on average - typically a diuretic and two drugs from the following classes: beta-blockers, ACE inhibitors, and calcium-channel blockers. Patients in the less-aggressive treatment group got only two drugs on average.
In the group with higher blood pressure, 210 out of 4,683 people died during the three years. But in the group given more medication to lower blood pressure, just 155 out of 4,678 died. That works out to a 27 percent lower risk of death from all causes over the course of the study.
And the rate of all cardiovascular events, including heart attack, stroke, and cardiovascular death, was 25 percent lower in the group that received aggressive treatment: 243 events in those 4,678 patients, compared with 319 events in the 4,683 that got less medicine.
Still, caution is warranted, given that the extra medicine was tied to an increase in fainting and kidney problems, said Phillip Koren, medical director of the Cooper Heart Institute in Camden.
"There is clearly a benefit in those outcomes, but it comes with a price," said Koren, who was not involved in the study. "That price is potentially significant."
Koren said he would take extra care to monitor patients before giving them additional medicine, being sure to measure their blood pressure both while sitting and standing, among other precautions. He said he would think twice before prescribing additional drugs to patients who are frail or prone to light-headedness when standing.
At a briefing Monday, study coauthor Paul K. Whelton said the risk of additional adverse events was worth the benefits seen in the trial.
"You're always looking at both sides of the ledger," said Whelton, a Tulane University physician. "But when you look at a 27 percent reduction in all-cause mortality, that is a very powerful potential benefit."
The study did not measure the possible impact of two other proven methods for lowering blood pressure: eating a healthy diet and getting enough exercise. However, physicians who enrolled patients for the study encouraged lifestyle modification, the authors wrote.
In an accompanying editorial, Boston University Medical Center's Aram V. Chobanian noted that physicians have had a hard time getting patients to improve these behaviors on a large scale.
Scientists caution against drawing conclusions from just one study, but the sheer size of the new trial means it will play a prominent role when medical societies next revise their blood-pressure guidelines.
Currently, people with high blood pressure and other cardiovascular risk factors are advised to shoot for a systolic pressure of 130.
Marc C. Cohen, an Abington Memorial Hospital cardiologist who reviewed the results of the new study, said they were strong enough on their own to make him shoot for 120 with certain patients.
He said the increased risk of kidney injury was worth scrutiny, but noted that the study authors found the problem appeared to be transient. As for the increase in fainting, it was not accompanied by an increased risk of injury from falls, Cohen noted.
Yet convincing patients to sign on for more drugs may be a challenge. Even under the current guidelines, millions of Americans fail to get their blood pressures under control. And worldwide, one billion people suffer from high blood pressure.
One reason is that some patients resist taking the medicines due to concerns about side effects, some of which are unfounded, Cohen said.
"People are reluctant, and doctors don't want to push," Cohen said.
But with results from the new study of more than 9,300 patients in hand, the NIH expects that physicians may want to push a bit more.